1. Technical Field
The invention relates generally to semiconductor devices, and more particularly, to a planar vertically extending resistor and/or a bond pad resistor that avoid miniaturization issues in semiconductor devices.
2. Background Art
Precision resistors have become essential for analog and mixed signal applications. Conventional metal back-end-of-line (BEOL) resistors are typically integrated as horizontal inserts in BEOL metal lines. FIG. 1 shows an illustrative conventional precision resistor 10. Precision resistor 10 is placed within a dielectric via layer 12 atop, for example, a silicon dioxide layer 14 and hydrogenated oxysilicon carbide layer (SiCOH) 16. An etch stop layer 20 covers resistor 10. As metal lines 22 have continued to be miniaturized, however, the thicknesses have approached dimensions that are close to or less than the thickness of precision resistor 10. As a result, continued use of horizontal resistors is impossible because it is unfeasible to insert the horizontal resistor in the thinner layers. For example, a via 24 on top of precision resistor 10 is as thin as resistor 10 such that a gap between metal line 22 is not large enough to include the via and the precision resistor.
In view of the foregoing, there is a need in the art for an alternative integration scheme and structure to provide precision resistors in BEOL wiring.